| 1. |
- Andersson-Engels, S., et al.
(author)
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Aspects of tumour demarcation in rats by means of laser-induced fluorescence and haematoporphyrin derivatives
- 1988
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In: Lasers in Medical Science. - 0268-8921. ; 3:239, s. 239-248
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Journal article (peer-reviewed)abstract
- The effects of different parameters of interest for the localization of malignant tumours in situ by means of laser-induced fluorescence and haematoporphyrin derivatives were investigated. Such parameters are drug composition, drug concentration, laser pulse energy and excitation wavelength. In order to assess the relative merits of the two tumour-seeking agents Photofrin (haematoporphyrin derivative) and Photofrin II (dihaematoporphyrin ether) we have performed a comparative study on rat tissues. The results suggest that Photofrin is at least as good as the therapeutically more potent agent Photofrin II. A linear relation between drug dose and recorded porphyrin fluorescence intensity was also found. Using not only the porphyrin fluorescence, but also natural tissue autofluorescence, better tumour demarcation is observed when utilizing an excitation wavelength shorter than the porphyrin excitation peak at 405 nm.
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| 2. |
- Andersson-Engels, Stefan, et al.
(author)
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Autofluorescence of various rodent tissues and human skin tumour samples
- 1987
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In: Lasers in Medical Science. - 0268-8921. ; 2:1, s. 41-49
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Journal article (peer-reviewed)abstract
- Fluorescence spectra from different organs in rats and mice have been recorded to explore the potential of non-intrusive tissue diagnostics. The fluorescence was induced by a nitrogen laser that emitted at a wavelength of 337 nm. Optical multichannel techniques were used for the detection. Spectra are given from 19 different sites in Wistar/Furth rats, including an inoculated malignant tumour. The spectra seem to be a sum of two wavelength distributions only, each distribution occurring with a different weight in different organs. Spectra obtained from living and dead tissue were compared to verify that the measurements on sacrificed experimental animals were valid. Preliminary results are given for some human tumours, transplanted in nude mice, and for some human skin samples.
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| 3. |
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| 4. |
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| 5. |
- Andersson-Engels, Stefan, et al.
(author)
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Integrated system for interstitial photodynamic therapy
- 2002
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In: Advanced Optical Devices, Technologies, and Medical Applications. - : SPIE. - 0277-786X .- 1996-756X. ; 5123, s. 293-302
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Conference paper (peer-reviewed)abstract
- To develop PDT beyond treatment of thin superficial tumours, to also be an efficient treatment alternative for deeply located and/or thick tumours, a system based on interstitial illumination using multiple fibres has been developed. Conditions that could benefit from such a treatment modality are for instance malignant brain tumours and tumours in the oral cavity. In interstitial PDT one needs to use multiple fibres for light delivery in order to allow treatments of tumours larger than a few millimetres in diameter. Our system consists of a laser light source, a beam-splitting system dividing the light into three or six output fibres and a custom-made dosimetry programme. The concept is then to use these fibres not only for delivering the treatment light but also to measure parameters of interest for the treatment outcome. The fluence rate of the light emitted by each fibre is measured at the positions of the other fibre tips. From these results the light dose at all positions could be recalculated. Changes in optical properties as well as bleaching and concentration of the photosensitizer during the treatment could be monitored and compensated for in the dosimetry. Tumours have been treated both in experimental studies and in patients with thick superficial Basal Cell Carcinomas. Almost all treated skin lesions responded with complete response.
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| 6. |
- Andersson-Engels, Stefan, et al.
(author)
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Laser Spectroscopy in Medical Diagnostics
- 1992
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In: Photodynamic Therapy: Basic Principles and Clinical Applications. - 0824786807 ; , s. 387-424
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Book chapter (peer-reviewed)
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| 7. |
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| 8. |
- Berg, R. C., et al.
(author)
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Barebacking among men who have sex with men recruited through a Swedish website: associations with sexual activities at last sexual encounter
- 2013
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In: Eurosurveillance. - 1560-7917. ; 18:13, s. 11-17
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Journal article (peer-reviewed)abstract
- The research topic of barebacking emerged in the mid-1990s. Since then, a multitude of studies, largely from the United States, have produced invaluable knowledge of factors that help explain the behaviour among men who have sex with men (MSM), and that may contribute to HIV risk reduction programming and advice to counsellors working with barebackers. Given the scant empirical research about barebacking among European MSM, we conducted a survey among 3,634 MSM recruited through a web community in Nordic countries. The objectives of the study were twofold: to describe the sexual activities associated with barebacking behaviour at last sexual encounter, and to evaluate the relationship of barebacking with relevant variables. Men who reported barebacking (n=356) and men who did not (n=3,278) were compared. On the basis of the results of the analyses, the socio-sexual profile of barebackers drawn was one that is at increased risk of acquiring human immunodeficiency virus (HIV) and other sexually transmitted infections due to their sexual practices, particularly unprotected anal intercourse, but also group sex and rimming. In a multivariate logistic regression analysis, the likelihood of engaging in barebacking was higher for MSM who reported more frequent HIV testing (odds ratio (OR)=5.16), a higher number of female sex partners (OR=16.80), using gay cruising places (OR=1.51) and gay chat rooms (OR=2.11).
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| 9. |
- Berg, R, et al.
(author)
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Medical Transillumination Imaging Using Short-pulse Diode-lasers
- 1993
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In: Optical Society of America. Journal B: Optical Physics. - 0740-3224. ; 32:4, s. 574-579
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Journal article (peer-reviewed)abstract
- The recently introduced time-resolved technique for enhanced medical transillumination imaging has been demonstrated for the important case of a diode laser transmitter. This type of gated-viewing technique utilizes early received light only to reject multiply scattered, delayed light, normally blurring the image. Human breast-cancer detection is demonstrated in vitro, and the observations are explained by using theoretical modeling and tissue phantom experiments.
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| 10. |
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